Answer:
Because they were suffering.
They studied fossils (paleontology) and applied the principle that old layers or rock are lying just below young layers
<span>The first recorded topographical maps issued by the government were based on the East Coast, of Boston Harbor, in 1846. A decade previous, however, in 1835, the Geological and Topographical Survey of Maryland had created a map of Maryland where the relief was shown by visual contour lines, and this 1835 map is considered the first state-issue topographical map.</span>